Automatic tension control for letoff mechanism of looms



I Aug. 7, 1945, Y Y. H. KURKJIAN/ AUTOMATIC TENSION CONTROL FOR LET-OFFMECHANISM OF LOOMS Filed Jan. 25, 1944 Patented Aug; 7; 1945 UNITEDSTATES PATENT OFF-ICE AUTOMATIC TENSION CONTROL FOR i 'LETOFF MECHANISMOF LOOMS Yervant H. Kurkjian, Clifton, N. J. Application January 25,1944, Serial N 0. 519,664

6 Claims.

This invention relates to an automatic control for the let-off mechanismof looms, and the like, and has for one of its objects the production ofa simple and efiicient mechanism which will control the tension of thebrake band of thewarp beam m a proper manner to maintain a uniformtension of the warp threads carried by the warp beam. c r j A furtherobject of this invention is the production of a simpleand eflicientmeans for shifting the position of the connection of the brake band withrespect to the tension control means in a manner to maintain a uniformtension upon the warp threads which are carried by the warp beam of aloom. i

Other objectsandadvantages of the present in- Figure '2'isan irregularsectional view taken.

on line 2-2 of Figure 1; t

Figure 3 is an enlarged vertical sectional view taken on line 3-3 ofFigure 1;

Figure 4 a side elevational viewof a modified form of my device; l s

Figure 5 is a vertical sectional view taken on line 5-5 of Figure 4.'

By referring to the'drawing, itwill be seen that designates theframe ofthe loom of a conventional 'type;-which carries the warp beam H of the:conventional type. "Sincethe present invention relates to theautomaticlet-ofi control mechanism, and not to the general loomconstructicn, no effortis made to illustrate the detail construction ofthe loom itself, and only those parts vital to the invention areillustrated and described." 1

A tension control arm i2 is carried by a shaft |3 rotatably mounted onthe frame l0, as shown in Figures 1 and 2. i This arm l2 carries a warpcontact roller M, at vits upper or outer end for direct contact with thewarp threads which are wound upon the warp beam II. A brake drum l5 iscarried by thebeam I i, and a brake band l6 passesover the drum l5, andis anchored at one end I! to the frame H1. The opposite end of the brakeband H5 is secured to a brake band connecting link I8." The-lower end ofthe link I8 carries a journal spin l9which is slidably mounted through ahorizontal slot 2|] formed in one end of the tension lever 2|. Thislever 2| is pivoted to the frame [0, as at 22.

The tension control arm I2 is carried by a suitable shaft l3, as stated,which shaft also carries a tension arm 23v which is located just abovethe inner end of the tension lever 2|. A tension spring 25 connects thetension arm 23 and the inner end-24 of the tension lever 2|, as shown inFigure 1; The shaft |3x also carries a depending finger-26 to which ispivotally connected a shifting rod 21 and this rod 21 isconnected at itsopposite end to the pin I9 which forms the lower end of the brake bandconnecting link I8.

' By considering Figures 1, 2 and 3, it will be noted that as the warpis unwound from the beam H, the control arm|2 willswing inwardlytowardthe warp to continue to contact the Warp.

As the arm l2 swings inwardly, the'tension arm 23 will swing downwardlythereby adjusting the tension upon the spring 25 and allowing thetension lever 2| to'slightly release pressure upon the brake band 16'.At the same time the depending finger 26'swings toward'the link It andthe shifting rod 21 will shift the journal pin IQ of the link 18longitudinallyof the slot 20 and increase the distance of the link I8from the pivot 22 and thereby decrease the leverage ex-' erted by thetension lever 2| ,upon the brake band l6.

In Figures 4 and 5 there is shown a modified form of automatic controlwherein an designates the frame of the loom above which is supported thebeam 3!; The Warp W is wound upon the beam 3| and this warp is engagedby a tension control arm 32 which is carried by a shaft 33 rotatablysupported upon the frame 30. The arm 32 is carried inside of theirame 30in a position to contact the warp. This shaft 33 carries anupwardlyextendin'g vfinger 34 and a laterally extending tension arm- 35,both of which are located outside of one end of the frame 3|],

as shown in Figure 4. I 1

A compound leverage assembly 36 is carried by the frame just above thefinger 34" and this leverage assembly 36 comprisesa primary lever 31 anda secondary lever 38. Thelever 31 is pivoted, as at 39, to the frame 30and thelever 38 is pivoted at 4-0 to theframe 30. These levers arearranged in longitudinal alignment as shown. The outer end ,M or lever31 is connected to one end of a tension spring 42 and the opposite endof the spring 42 is connected to the tension arm 35. The levers 31 and38 are provided with overlapping the adjoining lever. A sliding shoe 44frictionally engages the under face of the lever 38 near its outer endbeyond and under the pivot 40. A brake band 45 is anchored at one end tothe frame 30 and the opposite end of the band 45 engages a link 46. Thislink 46 detachably fits into the notch 41 of the shoe 44. This shoe 44is engaged by one end of the shifting rod or link 48, the opposite endof the link 48 being pivotally connected to the finger 34.

As the warp 32 is unwoundfrom the beam 31, the arm 32 swings inwardlythereby swinging the tension arm 35 upwardly and releasing tension ofthe spring 42 and also releasing tension upon the compound leverageassembly 36. At the same time the shoe 44 is moved outwardly of theouter end of the lever 38 increasing the lever arm beyond the pivot 40and further releasing tension upon the brake band 46.

Having described the claimed is:

invention, what is 1. An automatic let-off control of the classdescribed comprising a beam, a warp carried by the beam, a tensioncontrol arm contacting and controlled by the amount of warp carried bythe beam, a brake means for said beam, a lever means controlling thebrake, tension means connecting the lever means with the arm to hold thearm at all times in contact with the warp, the movement of the arm beingadapted to automatically control the pressure upon said brake controllever means to maintain a uniform tension upon the warp, connectingmeans between the brake and the lever means, and means linking said armwith said connecting means for automatically shifting the connectingmeans relative to the lever means to automatically adjust the leverageof said lever means as said arm is swung.

2. An automatic let-off control of the class described comprising abeam, a warp carried by the beam, a tension control arm contacting andcontrolled by the amount of warp carried by the beam, a brake means forsaid beam, lever means controlling the brake, tensionmeans connectingthe lever means with the arm to hold the arm at all times in contactwith the warp, the movement of the arm being adapted to automaticallycontrol the pressure upon said brake control lever means to maintain auniform tension upon the warp, a substantially horizontally slidableconnection for attaching the brake means with said lever means, and aconnection between said arm and said slidable connection for adjustingthe slidable connection longitudinally of said levermeans as said arm ismoved for regulating the tension upon said brake means.

3. An automatic let-off control of the class described comprising abeam,-a warp carried by the beam, a tension control arm contacting andcontrolled by the amount of warp carried by the beam, a brake means forsaid beam, lever means controlling the brake, tension means connectingthe lever means with the arm to hold the arm at all times in contactwith the warp, the movement of the arm being adapted to automaticallycontrol the pressure upon said brake control lever means to maintain auniform tension upon the warp, a substantially horizontally slidablereleasable connection for attaching the brake means with said levermeans, and a connection between said arm and said slidable connectionfor adjusting the slidable connection longitudinally of said lever meansas said arm is moved for regulating the tension upon said brake means.

4. An automatic let-off control of the class described comprising abeam, a warp carried by the beam, a tension control arm contacting andcontrolled by the amount of warp carried by the beam, a brake means forsaid beam, lever means controlling the brake, tension means connectingthe lever meanswith the arm to hold the arm at all times in contact withthe warp, the movement of the arm being adapted to automatically controlthe pressure upon said brake control lever means to maintain a uniformtension upon the warp, a substantially horizontally slidable connectionfor attaching the brake means with said lever means, a connectionbetween said arm and said slidable connection for adjusting the slidableconnection longitudinally of said lever means as said arm is moved forregulating the tension upon said brake means, and a link connected tothe brake means and engaging said slidable connection.

5. An automatic let-off control of the class described comprising abeam, a warp carried by the beam, a tension control arm contacting andcontrolled by the amount of warp carried by the beam, a brake means forsaid beam, lever means controlling the brake, tension means connectingthe lever means with the arm to hold the arm at all times in contactwith the warp, the movement of the arm being adapted to automaticallycontrol the pressure upon said brake control lever means to maintain auniform tension upon the warp, a substantially horizontally slidableconnection for attaching the brake means with said lever means, aconnection between said arm and said slidable connection for adjustingthe slidable connection longitudinally of said lever means as said armis moved for regulating the tension upon said brake means, a linkconnected to the brake means and engaging said slidable connection, andsaid slidable connection comprising a longitudinal slot formed in oneend of said lever means and said link fitting insaid slot.

6. An automatic let-01f control of the class described comprising abeam, a warp carried by the beam, a tension control arm contacting andcontrolled b the amount of warp carried by the beam, a brake means forsaid beam, lever means controllingthebrake, tension means connecting thelever means with the .arm to hold the arm at all times in contact withthe warp, the movement of the arm being adapted to automatically controlthe pressure upon said brake control lever means to maintain a uniformtension upon the warp, a substantially horizontally slidable connetcionfor attaching the brake means with said lever means, a connectionbetween said arm and said slidable connection for adjusting the slidableconnection longitudinally of said lever means as said arm is moved forregulating the tension upon said brake means, a link connected to thebrake means and engaging said slidable connection, and said slidableconnection comprising a slidable shoe fitting against the under side ofsaid lever means near the outer end thereof, and a link carried by thebrake means for engaging a receiving means carried by the shoe.

YERVANT H. KURKJIAN.

